1. Field of the Invention
The present invention relates to a test strip which allows a user to determine the concentration of an analyte in a liquid test sample. The test strip includes an absorbent membrane and a reagent that undergoes a change in color when exposed to the analyte, such as glucose or cholesterol, in a body fluid.
2. Description of Related Art
Test strips are commonly used for determining the concentration of analytes in liquid test samples. For example, known test strips can detect glucose, cholesterol, proteins, ketones, uric acid, phenylalanine, or enzymes in body fluids, such as blood or urine. The operation of such test strips has become so simple and reliable that the test strips can be used by patients to determine their own analyte concentrations.
Many test strips require a user to apply a drop of a body fluid to a reagent pad, or to a transport medium which conducts the fluid to the reagent pad, where an oxidizable dye or other indicator changes color to signal the presence of the analyte. It is sometimes difficult to bring exactly the right amount of body fluid to the test strip. If too little fluid is delivered, the test strip may not function properly. If too much fluid is applied to the test strip, excess fluid may drip from the test strip. Unnecessary contact between the user and the body fluid, which is typically blood, urine, or saliva, is preferably avoided.